docs: def convert_msg(self, msg):
          """
          Takes one POEntry object and converts it (adds a dummy translation to it)
          msg is an instance of polib.POEntry
          """
          source = msg.msgid
          if not source:
              # don't translate empty string
              return
  
          plural = msg.msgid_plural
          if plural:
              # translate singular and plural
              foreign_single = self.convert(source)
              foreign_plural = self.convert(plural)
              plural = {
                  '0': self.final_newline(source, foreign_single),
                  '1': self.final_newline(plural, foreign_plural),
              }
              msg.msgstr_plural = plural
          else:
              foreign = self.convert(source)
              msg.msgstr = self.final_newline(source, foreign)